FIG. 1 through FIG. 3 show the structures of the disc case which can be used for the recording disc reproducing device according to the present invention, wherein a disc case 1 in the shape of a rectangle is composed of a disc case body 2 (hereinafter referred to as the case) and a cover 3 to be detachably combined with the opening 7 provided at the front side of the inserting direction X.sub.1 toward the device of the case 2. The case 2 and the cover 3 are formed for example from styrol resin.
The case 2 is formed by a pair of half bodies 4 which are molded by the same die and pasted together, the inside of which is provided with the disc holding space 5 (whose height is a little greater than the thickness of the disc 6) which is flat over its entire width and length, and the disc 6 (a recording medium) is held in this space 5. This space 5 has the opening 7 on the side of the inserting direction X.sub.1 and the sides of the remaining three directions are blocked.
Further, the same components of the case 2 are so disposed as to be positioned at right and left sides with respect to the centerline l as the center in the inserting direction.
Each half body 4 consists of a plate 8 having recessions 17 on the right and left sides (which serve to cause a hinge action as will be described below) and the ribs 9, 10, 11 provided along the three edges of this plate. With respect to the lower half body 4 shown in FIG. 1, the windows 12, with which the later described opening arms engage, are formed at right and left sides in the neighborhood on the side of the opening 7 and the holes 13, with which the later described bosses of the cover engage, are formed at the central portion in the neighborhood of the opening 7. A pair of tapers 14 are formed symmetrically on the edges of the opening 7. Such tapers are for guiding the insertion of the arms of the later described latching mechanisms. At the inner portion the stoppers 15, to which the disc 6 butts, are formed at the positions deviated toward right and left from the centerline l.
Furthermore, on the inside in the neighborhood of the opening of the ribs 9, 10, recessions 16 are provided with which the later described bosses of the cover 3 engage. The half bodies 4, thus formed, are bonded together with an adhesive which is wholly or partially applied to the periphery of the ribs 9, 10, 11.
At the end of the cover 3, a flange 18 is provided to close the opening 7 of the case 2 when the cover 3 is engaged and secured with the case 2. The cover includes notches 19 into which the later described opening arms can enter, slopes 27 which guide the later described disc holding arm in the reproducing device, and guide grooves 20 having thin portions 28 which are thinner than the glue guard of the disc 6 and are formed symmetrically to the centerline l on both faces. Bosses 21 are formed on the centerline l of both faces which engage with the holes 13 of said case 2. Furthermore, slopes 22 and tapers 23 are provided to guide the cover 3 as it enters the case 2. Protuberances 24 are provided which engage with said recessions 16 to thereby fix the cover 3 to the case 2. Arms 25, having the flexibility of resin, are provided at their ends with slopes 26 which engage with the releasing members of the cover 3.
FIG. 2 shows the conditions of the disc 6 and cover 3 as assembled into the case 2. Such conditions are illustrated with respect to FIG. 1, wherein the disc 6 butts against the stoppers 15 to be secured in the direction of depth and secured as well as by the ribs 9, 10 in the direction of width.
The cover 3 closes the opening 7 and is joined together therewith by the protuberances 24 engaging with the recessions 16 and by the bosses 21 engaging with the holes 13.
With the cover thus closed, the disc 6 is limited in movement by the circular arcs 29 of the cover 3 with respect to the inserting direction X.sub.1 as well, so that the disc 6 is held in the case 2 without falling out therefrom. Furthermore, the thickness of the portion of the cover 3 entering the case 2 is almost the same as the thickness of the disc holding space 5 of the case 2 and the disc 6 will not therefore fall through the clearance therebetween.
FIG. 3 is a detail view of portions of the cover 3, wherein the shape opposing the disc 6 is formed by circular arc which, for example, provides greater clearances `b` at both ends as compared to the clearance `a` at the central portion. This spacing allows the disc 6 to operate stably even if the cover 3 and the record 6 are displaced from their relative positions more or less in the directions Z shown by the arrows.
FIG. 4 is a schematic illustration of an example of the conventional recording disc reproducing device which uses the disc case as mentioned above. This reproducing device 50 has such mechanisms as an opening mechanism 51 which expands to open the opening 7 of the case 2, a turntable 52 on which the disc 6 is placed, a mechanism 53 which holds the disc 6 and mechanisms 54 which latch the cover 3. The opening mechanism 51 of the case 2 is located in the neighborhood of the disc case inserting slot 55 of the reproducing device 50 and both sides of the opening mechanism 51 are guided by the guide rails 56 to move reversibly in the directions of X.sub.1 and X.sub.2 shown by the arrows. This opening mechanism 51 consists of the upper beam 57 and the lower beam 58 which extend in the direction of width of the reproducing device 50, each beam 57 and 58 are pivotally connected at each end to a moving body 51a which slides over said guide rails 56, by means of pivot pins 57b, 58b (refer to FIG. 5), and has the protuberances 57a, 58a which cooperate with a pair of opening arms 59 to engage the holes 13 of the case. Each beam 57, 58, when located in the neighbourhood of the disc case inserting slot 55, is slanted so as to cause the opening arms 59 of both beams 57, 58 to be held together by the action of the coil spring or the like.
As the opening mechanism 51 moves in the direction X.sub.1 (shown by the arrow) and the rollers 61, which are rotatably attached to the beams 57 and 58, ride over the tapers 62 formed at the ends of the guide rails 56 and then respectively rotate so as to be over the horizontal top surfaces thereof such that the beams 57 and 58 pivot and the opening arms 59 separate in the vertical direction away from each other.
In the construction as described above, when the disc case 1 is inserted into the reproducing device 50 through the slot 55 with the cover 3 facing the front, the opening arms 59, which are closed, enter the notches 19 of the cover 3, and the case opening mechanism 51 is pushed by the inserting motion of the cartridge to thereby move in the direction of the arrow X.sub.1.
Furthermore, the opening arms 59 are caused to enter the case 2 by the action of the tapers 14 provided at the opening 7 of the case 2. At this time, the tips of the opening arms 59 are positioned at respective locations corresponding to the windows 12 of the case 2. When the case opening mechanism 51 is moved, the opening arms 59 are rotated in the direction shown by arrow F wherein they move away from each other and as the case 2 is expanded the protuberances 57a, 58a engage with the holes 13 in the case to thereby expand and open the case 2. Hereafter, the case 2 is inserted into the direction of the arrow X.sub.1 as held in expanded and opened condition. Thus, since the case 2 is provided with the recessions 17 as mentioned above, expanding and opening actions of the above are interlocked by the inserting motion with relatively light force. Since the protuberances 24 of said cover 3 are engaged with the recessions 16 of the case 2 in the expanded and opened condition as well, the cover 3 moves together with the case 2. Thus, a situation is avoided wherein only the cover 3 is left in the reproducing device 50, even if the case is pulled out halfway. Furthermore, structures and motions of the turntable 52, holding mechanism 53, cover latching mechanisms 54 as well as those of other mechanisms are the same, such as, for example those of the prior art stated in the Japanese laid open Pat. No. 57-205853.
However, in the opening mechanism 51 of said prior art, there is the following problem, i.e., FIGS. 5a and b illustrate the motions of the opening mechanism 51 in relation to the disc case 1 while the motions of the opening mechanism 51 are as described above. Therefore, explanations will be given in stages so as to clarify problems which occur specifically in the example of the prior art.
FIG. 5a is illustrative of the condition of the case 2 before it butts against the opening mechanism 51. In this condition, as the case 2 butts against the opening mechanism 51 in the direction shown by the arrow E, the beams 57, 58 rotate in the direction shown by arrow F due to the action of the tapers 62 (refer to FIG. 4) to thereby expand and open the case.
FIG. 5b shows the condition of the case 2 being expanded to open, i.e., this is the condition wherein the rollers 61 are midway on the tapers 62 in FIG. 4. In this condition, the protuberances 57a, 58a are not yet engaged with the holes 13 of the case 2. However, since the rollers 61 are midway on the tapers 62, the rollers 61 can be returned to the condition shown in FIG. 5a by the action of said coil spring or the like.
Expansion and opening of the case 2 proceed further, which are shown in FIG. 5c, until it is in the completely expanded and opened condition. In such a condition, the protuberances 57a, 58a are now engaged with the holes 13 of the case 2.
Under the normal using conditions on the part of users, the opening mechanism 51 operates as shown in (a), (b), (c) of FIG. 5 above. Furthermore, as the case is being taken out, the opening mechanism 51 operates in reverse order of the motions shown in (c) to (b) to (a) of FIG. 5. However, there may be cases in which users put in and take out the disc case 1 at an abnormally fast speed and the opening mechanism 51 is vibrated in the neighborhood of the slot 55 causing the opening mechanism 51 to operate in such order as (a) to (b) to (c) or (c) to (b) to (a). Under such operation, because the opening mechanism 51 has inertia to some extent, the opening mechanism 51 alone runs into the direction of the arrow E due to the impact given by the case 2 as it butts against the opening mechanism 51. As such, the holes 13 of the case 2 are not engaged completely with the protuberances 57a, 58a as shown in FIG. 5c but instead are in the condition shown in FIG. 5d. In other words, in spite of the case being in the neighborhood of the slot 55, the opening mechanism 51 will be positioned inside the reproducing device 50.
If the operation is under such a condition, the rollers 61 have completely ridden past the tapers 62 and it is impossible for the opening mechanism 51 to return to the neighborhood of the slot 55 by the force of said coil spring and the like.
Under such a condition, it is also impossible to insert the case 2 over again to thereby cause the opening mechanism 51 to normally operate therefore the reproducing device 50 must be overhauled and repaired so as to put the opening mechanism 51 back into the normal operating conditon. Namely, should abnormal conditions such as above occur once, the normal conditions cannot be resumed by the users thereby making it impossible to reproduce the disc. Of course, such abnormal conditions do not necessarily occur frequently, but they are the problems which exist and must be solved in order to improve the reliability of the recording device since such conditions can result in considerable trouble should they happen even once.